NON-LINEAR ANALYSIS OF STEEL FIBER REINFORCED CONCRETE HOLLOW COLUMNS UNDER UNIAXIAL BENDING

Abstract

This study investigates the performance of Steel Fiber Reinforced concrete hollow columns under axial compressive load and uniaxial bending with varying amounts of steel fiber using Finite Element Method of Analysis. The columns are of two groups, one with a 10% void and the other group has 20% void at the center. Each group’s specimens’ fiber content is varied in 0.5% increments from 0 to 1.5%. Also, the collapse load of the columns was obtained. Numerical results were compared with the available experiments. Two parametric studies were conducted by varying the amount of void percentages and steel fiber contents. In the first study, a 30% hollow section was analyzed by varying steel fiber content in 0.5% increments from 0.5% to 2.5%. Secondly, the hollow opening for 10%, 20% and 30% was compared with a constant steel fiber of 1.5% by volume. It was observed that introduction of a hollow opening reduces the capacity of the section and the loss in strength is proportionate to the opening size. Adding steel fibers provide ductility to the section by increasing the first-cracking load and also increasing the collapse load of the specimen. For openings within 10%, adding 0.5% steel fibers by volume yields strength results similar to a solid section without any steel fibers, and for openings within 20%, adding 1.5% steel fibers by volume yields strength results similar to a solid section without any steel fibers. Similar results were observed in the parametric study.